Lecture 2 - Clincal Trials Flashcards
What is the problem with not having a control group in a study?
Not easy to compare how well a certain treatment works
What is the definition of a clinical trial?
Any form of planned experiment which involves patients and is designed to decide the most appropriate method of treatment for future patients with a given condition
What is the purpose of a clinical trial?
To provide reliable evidence of treatment efficacy and saftey
What are the stages to drug development and monitoring?
Pre clinical phase
Phase 1 = volunteer studies
Phase 2 = treatment studies
Phase 3 = clinical trials
Phase 4 = post marketing surveillance
What is the purpose of phase 3 clinical trials?
Comparison of the new drug with standard a;ready existing treatments
What is the purpose of phase 1 volunteer studies?
Pharmacodynamics
Phhharmacokinetics
Major side effects
What is the purpose of phase 2 treatment studies?
Effects and dosages
Common side effects
What is the purpose of phase 4 post marketing surveillance?
Monitoring for adverse reaction and potential new uses
What are the most importnat ethical considerations for any trial to go ahead?
Trials of new drugs may do harm
The patients must given informed constent so must understand risk involved
What is clinical equipoise?
When we are very unsure on whether a new drug will be more effective if given so we will only know if we trial it
What is a non-randomised clinical trial?
When the way patients are allocated to receive a new treatment versus the standard treatment (the controls) is non random (you chose who gets the treatment)
What is comparison with historical controls in non randomised clinical trials?
All future patients may get new treatment and their outcomes are compared with patients in th least 6 months who were given standard treatment
What is there problem with the historical control group in non-randomised clinical trials?
Selection is often less well defined
Treated differently from new treatment group
Less info on potential con founders
Can control for confoudners
What is the advantages of randomisation for clinical trials?
Minimises affects of confounding
What is a confounded/confounding?
When there is a third factor that is associated with the exposure and the outcome and that distorts the relationship between them
What is a common confounder between alcohol and MI?
Smoking
Since alcohol does increase risk of MI
But if you drink you’re more likely to smoke and smoking increases risk of MI
What are some ways randomisation can be carried out?
Toss a coin
Random number tables
Sequentially numbered sealed envelopes containing the random allocation as participants are recruited
Why is sample size important in a random clinical trial?
Larger sample sizes help reduce the affect of confounding keeping trials as fair as possible
What are the key features for a clinical trial to be fair and safe?
Reproducible
Controlled (intervention and comparison group)
Fair (unbiased without confounding)